Shaft Structure in a Pneumatic Actuator

ABSTRACT

An improved structure of a central shaft in a pneumatic actuator comprises an actuator having an actuator chamber; a vane which is hingedly located at a shaft hole of the actuator. The central shaft is cylindrical and short, and the short central shaft has a through hole which is a through octagonal opening symmetric to a center thereof. It can be easily processed and precisely aligned. The advantage of the short central shaft is that the actuator itself can connect to non-pressured sources such as an upper and lower central shafts, and connect to different inserting drivers to form a central shaft as a unit in the pneumatic actuator to directly connect to a central shaft of a valve or indirectly through a connecting bracket instead of using a conventional connecting coupler. The octagonal opening provides alignment positions at every 45 degrees for the upper and lower central shafts to increase diversities of usage.

FIELD OF THE INVENTION

This invention relates to a technology area of a central shaft in a pneumatic actuator (actuator), and more particularly to an improved structure of the central shaft in the actuator, wherein the central shaft is a cylinder with an octagonal through hole symmetrically located to a center thereof to assure that an upper and a lower central shaft can align to the center.

BACKGROUND OF THE INVENTION

Conventionally, an actuator vane (90) in a vane chamber is shown in FIG. 5, wherein a central shaft (91) and a blade (92) are manufactured as one unit, and it may be difficult to concentrically align two ends of the central shaft (91) and to drive them simultaneously. Usually, it should be coupled with a connecting bracket and a connecting coupler. However, there are so many kinds of connecting coupler as to style, size and angle. Moreover, current ball valves have many non-square rod ends which may be used when coupling with a transition coupler. If the two ends of the transition coupler are a protruding rod and a recessed hole respectively, the recessed hole would be a blind hole which is not easy to be further processed. Also, the protruding rod and the recessed hole are difficult to be aligned concentrically and the ball valve cannot be effectively sealed.

SUMMARY OF THE INVENTION

The technical problem to be solved in the present invention is that a conventional actuator vane (90) in a vane chamber as shown in FIG. 5 has a central shaft (91) and a blade (92) manufactured as one unit, and it may be difficult to concentrically align two ends of the central shaft (91) and to drive them simultaneously. Usually, it should be coupled with a connecting bracket and a connecting coupler. However, there are so many kinds of connecting coupler as to style, size and angle. If the actuator is equipped with a connecting bracket, the connecting coupler has to be rotated for compensational adjustment when the actuator is worn, and it is very inconvenient to rotate or adjust the connecting coupler because most parts have to be dissembled. Moreover, current ball valve has many non-square rod ends which may be used when coupling with a transition coupler. If the two ends of the transition coupler are a protruding rod and a recessed hole respectively, the recessed hole would be a blind hole, which is uneasy to be further processed. Also, the protruding rod and the recessed hole are difficult to be aligned concentrically and the ball valve cannot be effectively sealed.

The technical point to solve the abovementioned problem is to provide an improved structure for a central shaft in the pneumatic actuator, including: a vane, which has a blade and a short central shaft having a through octagonal opening symmetric to a center thereof; an upper central shaft, which has a first square block adapted to insert into the through octagonal opening to occupy four corners symmetric to the center of the octagonal opening, and a non-through inner screw hole inside a bottom surface of the square block; a lower central shaft, which has a second square block corresponding to the symmetric center of the through octagonal opening, wherein the second square block is inserted into the through octagonal opening to occupy four corners symmetric to the center of the octagonal opening, and the second square block has a through hole inside a top surface thereof, and a bottom surface of the lower central shaft has an upward circular opening which has a key groove around the periphery of the circular opening; and an inserting driver, which has a through assembled opening at a center thereof and is designed as a cylinder equal to the upward circular opening of the lower central shaft, and a key slot is formed at a surrounding surface, wherein the inserting driver is configured to be inserted into the circular opening of the lower central shaft; a key element, which is located at the key groove of the lower central shaft and the key slot of the inserting driver; a screw which is fastened at the inner screw hole of the upper central shaft through the through hole of the lower central shaft and the through octagonal opening of the short central shaft to form a central shaft as a seamless central shaft.

Contrast to the conventional techniques, the improved structure in the pneumatic actuator in the present invention has a short central shaft which is made by drilling an entire circular rod along with broaching to manufacture a through octagonal opening symmetric to the center, which allows precise and easy concentric processing. Furthermore, since the short central shaft in the present invention is a cylinder, it can be easily aligned. Also, the inserting driver is not a blind hole so it can be precisely and easily processed. The through hole and circular hole of the lower central shaft are all circularly processed so the alignment is precise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a three-dimensional exploded view of one embodiment of the present invention;

FIG. 2 is a sectional view of the assembled shaft connecting to the pneumatic actuator;

FIG. 3 is a sectional view of the assembled shaft connecting to the pneumatic actuator with a connecting bracket;

FIG. 4 is a sectional view of the assembled shaft connecting to the pneumatic actuator and connecting to two valve bodies; and

FIG. 5 is a three-dimensional view of a conventional vane.

DETAILED DESCRIPTION OF THE INVENTION

The detailed description set forth below is intended as a description of the presently exemplary device provided in accordance with aspects of the present invention and is not intended to represent the only forms in which the present invention may be prepared or utilized. It is to be understood, rather, that the same or equivalent functions and components may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices and materials similar or equivalent to those described can be used in the practice or testing of the invention, the exemplary methods, devices and materials are now described.

All publications mentioned are incorporated by reference for the purpose of describing and disclosing, for example, the designs and methodologies that are described in the publications which might be used in connection with the presently described invention. The publications listed or discussed above, below and throughout the text are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.

Referring to FIGS. 1 to 4, this invention provides an improved structure of a central shaft in a pneumatic actuator, including:

a vane (10), which has a blade (11) and a short central shaft (12) having a through octagonal opening (121) symmetric to a center;

an upper central shaft (20), which has a first square block (21) corresponding to the symmetric center of the through octagonal opening (121), wherein the first square block is inserted into the through octagonal opening (121) to occupy four corners symmetric to the center of the octagonal opening (121), and a non-through inner screw hole (211) is inside a bottom surface of the first square block (21);

a lower central shaft (30), which has a second square block (31) corresponding to the symmetric center of the through octagonal opening (121), wherein the second square block (31) is inserted into the through octagonal opening (121) to occupy four corners symmetric to the center of the through octagonal opening (121), and the second square block (31) has a through hole (32) inside a top surface thereof, and a bottom surface of the lower central shaft (30) has an upward circular opening (33) which has a key groove (331) around the periphery of the circular opening (33); and

an inserting driver (40), which has a through assembled opening (41) at a center thereof and is designed as a cylinder equal to the upward circular opening (33) of the lower central shaft (30), and a key slot (42) is formed at a surrounding surface, wherein the inserting driver (40) is configured to be inserted into the circular opening (33) of the lower central shaft (30); a key element (50), which is located at the key groove (331) of the lower central shaft (30) and the key slot (42) of the inserting driver (40); a screw (60) which is fastened at the inner screw hole (211) of the upper central shaft (20) through the through hole (32) of the lower central shaft (30) and the through octagonal opening (121) (which is center-symmetric) of the short central shaft (12).

The short central shaft (12) in a pneumatic actuator (34), as previously stated, can be connected to the upper and lower central shafts (20, 30) of a non-pressured source, and to the inserting driver (40) of diversities to form a complete central shaft of the actuator which can be connected to a central shaft of a valve directly or indirectly through a connecting unit, without using a conventional connecting coupler. Furthermore, the through octagonal opening (121) which is symmetric to its center provides a number of alignment positions every 45 degrees for the upper and lower central shafts (20, 30) to increase diversities of usage.

The through assembled opening (41) of the inserting driver (40), as previously illustrated, can be manufactured to any shape associated with the shape of a valve rod, and because the through assembled opening (41) is a through and non-blind opening, it is easy to manufacture.

The lower central shaft (30), as previously stated, can be connected to a first valve body (70), and the upper central shaft (20) can be connected to a second valve body (71).

The upper central shaft (20), as previously described, can be connected to a display monitor (not shown in the FIGs) which displays opening degrees of the inner valve.

The upper central shaft (20), as previously described, can be connected to a positioning device (not shown in the FIGs) which displays opening degrees of the inner valve.

The pneumatic actuator (34) located at the lower central shaft (30) can be equipped with a connecting bracket (35), and the lower central shaft (30) can directly replace the conventional connecting coupler to connect to the first valve body (70).

As illustrated above, it is convenient that the through octagonal opening (121) which is symmetric to the center can change the angle to 90 degrees or 45 degrees. The short central shaft (12) is circular which is easy to align to the center, and the upper central shaft (20) and the lower central shaft (30) have the inner screw hole (211) and the through hole (32), respectively, which are also very easy to align to the center.

Having described the invention by the description and illustrations above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Accordingly, the invention is not to be considered as limited by the foregoing description, but includes any equivalents.

KEY SYMBOLS IN THIS APPLICATION The Present Invention:

-   (10) Vane -   (11) Blade -   (12) Short central shaft -   (121) Through octagonal opening -   (20) Upper central shaft -   (21) First square block -   (211) Inner screw hole -   (30) Lower central shaft -   (31) Second square block -   (32) Through hole -   (33) Circular opening -   (331) Key groove -   (34) Actuator (Pneumatic actuator) -   (35) Connecting bracket -   (40) Inserting driver -   (41) Through assembled opening -   (42) Key slot -   (50) Key element -   (60) Screw -   (70) First valve body -   (71) Second valve body

Prior art:

-   (90) Actuator vane -   (91) Central shaft -   (92) Blade 

1. An improved structure of a central shaft in a pneumatic actuator, comprising: a vane, which has a short central shaft having a through octagonal opening symmetric to a center thereof; an upper central shaft, which has a first square block adapted to insert into the through octagonal opening to occupy four corners symmetric to the center of the octagonal opening, and a non-through inner screw hole inside a bottom surface of the square block; a lower central shaft, which has a second square block corresponding to the symmetric center of the through octagonal opening, wherein the second square block is inserted into the through octagonal opening to occupy four corners symmetric to the center of the octagonal opening, and the second square block has a through hole inside a top surface thereof, and a bottom surface of the lower central shaft has an upward circular opening which has a key groove around the periphery of the circular opening; and an inserting driver, which has a through assembled opening at a center thereof and is designed as a cylinder equal to the upward circular opening of the lower central shaft, and a key slot is formed at a surrounding surface, wherein the inserting driver is configured to be inserted into the circular opening of the lower central shaft; a key element, which is located at the key groove of the lower central shaft and the key slot of the inserting driver; a screw which is fastened at the inner screw hole of the upper central shaft through the through hole of the lower central shaft and the through octagonal opening symmetric to a center of the short central shaft.
 2. The improved structure of a central shaft in a pneumatic actuator of claim 1, wherein the through assembled opening of the inserting driver is a square opening, an octagonal opening, an oval-shaped opening or a polygonal opening.
 3. The improved structure of a central shaft in a pneumatic actuator of claim 1, wherein the lower central shaft is connected to a first valve body.
 4. The improved structure of a central shaft in a pneumatic actuator of claim 3, wherein the upper central shaft is connected to a display screen.
 5. The improved structure of a central shaft in a pneumatic actuator of claim 3, wherein the upper central shaft is connected to a positioning device.
 6. The improved structure of a central shaft in a pneumatic actuator of claim 3, wherein the upper central shaft is connected to a second valve body.
 7. The improved structure of a central shaft in a pneumatic actuator of claim 3, wherein the lower central shaft of the pneumatic actuator is equipped with a connecting bracket, and the lower central shaft longer than a conventional connecting coupler is chosen, so the lower central shaft is directly connected to the first valve body. 